EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: AndyC_772 on May 18, 2019, 07:20:36 am
-
Hi all,
I'm interested in getting some idea of how much power each circuit in my home is using, on average, over time. I don't need great accuracy, just some idea of where the big loads are which might be worth trying to reduce.
One way to do this would be to log the current using a clamp meter. It's important that it be able to record measurements at regular intervals over a period of time for later analysis.
I already have a Fluke 289 which has logging capability, so another option might be to use a separate current sensor with a calibrated output, and use them together.
Can anyone please suggest a clamp meter with logging capability, or a clamp-on current sensor, which might be suitable?
-
I've used the LEM AT series of self-powered clamp-on isolated sensors as input to PLC analog channel. The input resistance of the measuring device/logger or whatever needs to be high for rated accuracy, but can be lower if you want to calibrate the achieved readings, but can't be really low. Simple to set up, but you do need access to phase leads in the switchboard (eg. from distribution fuses or cbs), and although they are pretty small, there often isn't much room behind a switchboard panel. You can then use any logger of choice.
-
There are a lot of cheap (<5 dollars) current transformers on ebay/aliexpress, they are cheap enough to see if they are adequate for your needs. Of course you would measure Apparent power with the simplest approach of measuring the current and multiplying by the nominal voltage.
If you want a more permanent solution, perhaps something like:https://openenergymonitor.org/ (https://openenergymonitor.org/) could be for you.
-
I count the pulses on the mains counter device. 1 pulse = 1Wh.
send the pulse count each minute to thingspeak.com
this way you get a global view over time of your current consumption.
then, if I need better precision, I will add current transformers like below on each circuit breaker.
https://www.ebay.com/itm/5A-Range-Single-Phase-AC-Current-Transformer-Sensor-Module-for-Arduino/232548663694 (https://www.ebay.com/itm/5A-Range-Single-Phase-AC-Current-Transformer-Sensor-Module-for-Arduino/232548663694)
(https://i.ebayimg.com/images/g/x-0AAOSwUlxZ~C67/s-l1600.jpg)
-
(https://www.cjoint.com/doc/19_05/IEstEK0vNcz_IMG-0636.jpg)